使用复杂子查询在SQL中练习

Question

我正在尝试在SQL中执行查询。数据库是IMBD之一。这是形式：

所以，我需要从电影低俗小说（ID = 2175869），演员/女演员，从来没有与低俗小说的另一位演员/女演员没有其他影片共同担任。

它应该是这样的：

SELECT person_id FROM cast_info WHERE movie_id = 2175869 AND 
person_id NOT IN (SELECT) 

但我无法弄清楚如何做的第二部分。不是低俗小说等

Answer 1

查询后用作子查询，返回电影哪里低俗小说不止一个演员在其中扮演

SELECT movie_id 
FROM cast_info 
WHERE 
    movie_id <> 2175869 AND 
    person_id IN (SELECT person_id FROM cast_info WHERE movie_id = 2175869) 
GROUP BY movie_id 
HAVING COUNT(*) > 1 

现在得到低俗小说玩的人谁没有这样的电影玩

SELECT person_id 
FROM cast_info 
WHERE 
    movie_id = 2175869 AND 
    person_id NOT IN (
     SELECT person_id FROM cast_info WHERE movie_id IN (
      SELECT movie_id 
      FROM cast_info 
      WHERE 
       movie_id <> 2175869 AND 
       person_id IN (SELECT person_id FROM cast_info WHERE movie_id = 2175869) 
      GROUP BY movie_id 
      HAVING COUNT(*) > 1 
     ) 
    ) 

注：我假设一个演员只能在每部电影中铸造一次。如果同一个演员可以在同一部电影中担任不同的角色，请用COUNT(DISTINCT person_id)替换COUNT(*)。

Answer 2

首先，你需要看到低俗小说所有的演员：

SELECT person_id as pulp_actor_id 
FROM cast_info 
WHERE movie_id = 2175869 

然后，你需要找到所有的演员二重奏：

SELECT c1.person_id as actor1_id 
     c2.person_id as actor2_id 
FROM cast_info c1 
JOIN cast_info c2 
    ON c1.person_id < c2.person_id 
WHERE c1.movie_id = 2175869 
    AND c2.movie_id = 2175869; 

找到所有的电影，其中二人一起行动低俗小说旁。

SELECT actor1_id, actor2_id, actor1_movies.movie_id 
FROM (SELECT c1.person_id as actor1_id 
      c2.person_id as actor2_id 
     FROM cast_info c1 
     JOIN cast_info c2 
     ON c1.person_id < c2.person_id 
     WHERE c1.movie_id = 2175869 
     AND c2.movie_id = 2175869) as duos 
JOIN cast_info as actor1_movies 
    ON duos.actor1_id = actor1_movies.person_id 
AND actor1.movie_id <> 2175869 
LEFT JOIN cast_info actor2_movies 
    ON duos.actor2_id = actor2_movies.person_id 
AND actor1_movies.movie_id = actor2_movies.movie_id 
WHERE actor2.movie_id IS NOT NULL; 

现在得到所有从低俗小说演员不是最后的结果

SELECT person_id as pulp_actor_id 
FROM cast_info c 
LEFT JOIN (SELECT actor1_id, actor2_id, actor1_movies.movie_id 
      FROM (SELECT c1.person_id as actor1_id 
         c2.person_id as actor2_id 
        FROM cast_info c1 
        JOIN cast_info c2 
        ON c1.person_id < c2.person_id 
        WHERE c1.movie_id = 2175869 
        AND c2.movie_id = 2175869) as duos 
      JOIN cast_info as actor1_movies 
       ON duos.actor1_id = actor1_movies.person_id 
      AND actor1.movie_id <> 2175869 
      LEFT JOIN cast_info actor2_movies 
       ON duos.actor2_id = actor2_movies.person_id 
      AND actor1_movies.movie_id = actor2_movies.movie_id 
      WHERE actor2.movie_id IS NOT NULL; 
      WHERE movie_id = 2175869) as duos 
    ON c.person_id IN (actor1_id, actor2_id) 
WHERE duos.movie_id IS NULL